Diabetes and femoral neck strength: findings from the Hip Strength Across the Menopausal Transition Study

Femora of women with premature ovarian insufficiency exhibit reduced strength and misalignment with the transmitted vertical forces from the upper body

BACKGROUND

Women with premature ovarian insufficiency (POI) lack oestrogen, which is a key determinant of bone growth, epiphyseal closure, and bone tissue organisation. Although dual-energy X-ray absorptiometry (DXA)-derived areal bone mineral density (BMD) remains the gold standard for fracture risk evaluation, it does not fully characterise the skeletal abnormalities present in these women. Hence, we aimed to assess hip/femur anatomy, strength, and geometry and femoral alignment using advanced hip analysis (AHA).

METHODS

We conducted a cross-sectional, case-control study including 89 women with spontaneous normal karyotype POI (s-POI) or iatrogenic POI (i-POI), aged 20-50 years compared with 89 age- and body mass index (BMI)-matched population-based female controls. Hip anatomy, strength, geometrical parameters, and femur alignment were measured using hip DXA images and Lunar AHA software. Femoral orientation angle (FOA) was quantified as the overall orientation of the femur with respect to the axis of the forces transmitted from the upper body.

RESULTS

The median age of POI diagnosis was 35 (18-40) years; the mean POI duration at the time of DXA was 2.07 (range 0-13) years, and 84% of POI women received oestrogen therapy. Areal BMD at all sites was significantly lower in the POI group (all P < .05). Indices of compressive and bending strength were lower in women with POI compared with controls, specifically the cross-sectional area (CSA, mm2) and section modulus (SM, mm3) (139.30 ± 29.08 vs 157.29 ± 22.26, P < .001 and 665.21 ± 129.54 vs 575.53 ± 150.88, P < .001, respectively). The FOA was smaller (124.99 ± 3.18) in women with POI as compared with controls (128.04 ± 3.80; P < .001) at baseline and after adjusting for height and femoral neck BMD.

CONCLUSION

Alongside lower BMD at multiple sites, the femora of women with POI demonstrate reduced strength and a misalignment with forces transmitted from the upper body. Further research is needed to establish the role of these newly identified features and their role in fracture risk prediction in this population.

Use of noninvasive imaging to identify causes of skeletal fragility in adults with diabetes: a review

Diabetes, a disease marked by consistent high blood glucose levels, is associated with various complications such as neuropathy, nephropathy, retinopathy, and cardiovascular disease. Notably, skeletal fragility has emerged as a significant complication in both type 1 (T1D) and type 2 (T2D) diabetic patients. This review examines noninvasive imaging studies that evaluate skeletal outcomes in adults with T1D and T2D, emphasizing distinct skeletal phenotypes linked with each condition and pinpointing gaps in understanding bone health in diabetes. Although traditional DXA-BMD does not fully capture the increased fracture risk in diabetes, recent techniques such as quantitative computed tomography, peripheral quantitative computed tomography, high-resolution quantitative computed tomography, and MRI provide insights into 3D bone density, microstructure, and strength. Notably, existing studies present heterogeneous results possibly due to variations in design, outcome measures, and potential misclassification between T1D and T2D. Thus, the true nature of diabetic skeletal fragility is yet to be fully understood. As T1D and T2D are diverse conditions with heterogeneous subtypes, future research should delve deeper into skeletal fragility by diabetic phenotypes and focus on longitudinal studies in larger, diverse cohorts to elucidate the complex influence of T1D and T2D on bone health and fracture outcomes.

The nonlinear association between triglyceride glucose-body mass index and femoral neck BMD in nondiabetic elderly men: NHANES 2005-March 2020

BACKGROUND

The triglyceride glucose-body mass index (TyG-BMI) has been considered a surrogate marker for assessing insulin resistance. We aimed to correlate the TyG-BMI, triglyceride glucose combined with body mass index, with femoral neck bone mineral density (FN BMD) in non-diabetic elderly men.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) database, totally, 1182 eligible men aged ≥ 50 years without diabetes were included in the current study. Smoothed curves were obtained by a two-piecewise linear regression model and the threshold effects were explored by using a smoothing function.

RESULTS

TyG-BMI was positive related with and FN BMD with or without adjustment for confounders. However, no typical dose-dependent positive association between TyG-BMI and FN BMD was observed across the TyG-BMI tertiles, indicating a non-linear association. Further analysis by the weighted two-piecewise linear regression model and recursive algorithm suggested that per SD increase in TyG-BMI increased FN BMD by 0.266 gm/cm2 when TyG-BMI lower than 168.20. However, when TyG-BMI is higher than 168.20, FN BMD only increased 0.046 gm/cm2 for per SD increase of TyG-BMI after fully adjustment (OR = 11.258, 95%CI: 6.034, 16.481). Moreover, subgroup analyses showed that higher TyG-BMI levels were related to elevated FN BMD in all groups, suggesting the consistency of the positive association within these stratas.

CONCLUSIONS

This study demonstrated that TyG-BMI is positively associated with FN BMD in a nonlinear fashion among elderly men without diabetes, which may be a reliable marker for the early identification of individuals with lower FN BMD.

The effects of Gli1 and Gli2 on BMP9-induced osteogenic differentiation of mesenchymal stem cells

Diseases, such as bone nonunion with bone defects, osteoporosis, etc, seriously endanger people's quality of life, and bone tissue engineering based on mesenchymal stem cells is an effective method to solve such problems. Several studies have shown that BMP9 can effectively promote osteogenic differentiation of MSCs, but the underlying molecular mechanisms are still unclear. Gli1 and Gli2 were important transcription factors and play an important role in the Hedgehog signaling pathway. In this study, we investigated the role of Gli1 and Gli2 in BMP9-induced osteogenic differentiation of MSCs. We found that inhibition of Gli1 and Gli2 weakened BMP9-induced osteogenic differentiation of MSCs, and early osteogenic markers (alkaline phosphatase, ALP), late osteogenic markers (calcium salt deposition), the expression of pivotal osteogenic markers were attenuated, and inhibition of Gli1 and Gli2 weakened the expression of p-Smad1/5/8 and p-p38 induced by BMP9. In conclusion, our study shows that Gli1 and Gli2 play an important role in BMP9-induced osteogenic differentiation.

Associations of Type 2 Diabetes, Body Composition, and Insulin Resistance with Bone Parameters: The Dubbo Osteoporosis Epidemiology Study

Type 2 diabetes (T2D) may be associated with increased risk of fractures, despite preserved bone mineral density (BMD). Obesity and insulin resistance (IR) may have separate effects on bone turnover and bone strength, which contribute to skeletal fragility. We characterized and assessed the relative associations of obesity, body composition, IR, and T2D on bone turnover markers (BTMs), BMD, and advanced hip analysis (AHA). In this cross-sectional analysis of Dubbo Osteoporosis Epidemiology Study, 525 (61.3% women) participants were grouped according to T2D, IR (homeostasis model assessment insulin resistance [HOMA-IR] Collapse

Key Words

• BIOCHEMICAL MARKERS OF BONE TURNOVER
• BONE‐FAT INTERACTIONS
• DUAL‐ENERGY X‐RAY ABSORPTIOMETRY
• FRACTURE RISK ASSESSMENT
• STATISTICAL METHODS

Collapse

MESH Headings Collapse

Grants

• St. Vincent's Clinic Foundation

Collapse

Affiliation(s)

Angela Sheu Skeletal Diseases ProgramGarvan Institute of Medical ResearchSydneyNSWAustralia School of Clinical Medicine, UNSW Medicine and Health, St Vincent's Clinical Campus, Faculty of Medicine and HealthUNSW SydneySydneyNSWAustralia Department of Endocrinology and DiabetesSt Vincent's HospitalSydneyNSWAustralia
Robert D. Blank Skeletal Diseases ProgramGarvan Institute of Medical ResearchSydneyNSWAustralia
Thach Tran Skeletal Diseases ProgramGarvan Institute of Medical ResearchSydneyNSWAustralia School of Clinical Medicine, UNSW Medicine and Health, St Vincent's Clinical Campus, Faculty of Medicine and HealthUNSW SydneySydneyNSWAustralia
Dana Bliuc Skeletal Diseases ProgramGarvan Institute of Medical ResearchSydneyNSWAustralia School of Clinical Medicine, UNSW Medicine and Health, St Vincent's Clinical Campus, Faculty of Medicine and HealthUNSW SydneySydneyNSWAustralia
Jerry R. Greenfield Skeletal Diseases ProgramGarvan Institute of Medical ResearchSydneyNSWAustralia School of Clinical Medicine, UNSW Medicine and Health, St Vincent's Clinical Campus, Faculty of Medicine and HealthUNSW SydneySydneyNSWAustralia Department of Endocrinology and DiabetesSt Vincent's HospitalSydneyNSWAustralia
Christopher P. White School of Clinical Medicine, Prince of Wales Clinical Campus, Faculty of Medicine and HealthUNSW SydneySydneyNSWAustralia Department of Endocrinology and MetabolismPrince of Wales HospitalSydneyNSWAustralia
Jacqueline R. Center Skeletal Diseases ProgramGarvan Institute of Medical ResearchSydneyNSWAustralia School of Clinical Medicine, UNSW Medicine and Health, St Vincent's Clinical Campus, Faculty of Medicine and HealthUNSW SydneySydneyNSWAustralia Department of Endocrinology and DiabetesSt Vincent's HospitalSydneyNSWAustralia

Collapse

Type 2 diabetes mellitus plays a protective role against osteoporosis --mendelian randomization analysis

BACKGROUND

Type 2 diabetes mellitus (DM2) and osteoporosis (OP) are currently the two most significant causes of mortality and morbidity in older adults, according to clinical evidence. The intrinsic link between them is yet unknown, despite reports of their coexistence. By utilizing the two-sample Mendelian randomization (MR) approach, we sought to evaluate the causal impact of DM2 on OP.

METHODS

The aggregate data of the whole gene-wide association study (GWAS) were analyzed. A two-sample MR analysis was performed using single-nucleotide polymorphisms (SNPs), which are strongly associated with DM2, as instrumental variables (IVs) to evaluate the causal analysis of DM2 on OP risk with OR values, using inverse variance weighting, MR-egger regression, and weighted median methods, respectively.

RESULT

A total of 38 single nucleotide polymorphisms were included as tool variables. According to the results of inverse variance-weighted (IVW), we found that there was a causal relationship between DM2 and OP, in which DM2 had a protective effect on OP. For each additional case of DM2, there is a 0.15% decrease in the odds of developing OP (OR = 0.9985;95%confidence interval:0.9974,0.9995; P value = 0.0056). There was no evidence that the observed causal effect between DM2 and the risk of OP was affected by genetic pleiotropy (P = 0.299). Using Cochran Q statistics and MR-Egger regression in the IVW approach, the heterogeneity was calculated; P > 0.05 shows that there is a significant amount of heterogeneity.

CONCLUSION

A causal link between DM2 and OP was established by MR analysis, which also revealed that DM2 decreased the occurrence of OP.

Prediabetes and Fracture Risk Among Midlife Women in the Study of Women's Health Across the Nation

Importance

Whether prediabetes is associated with fracture is uncertain.

Objective

To evaluate whether prediabetes before the menopause transition (MT) is associated with incident fracture during and after the MT.

Design, Setting, and Participants

This cohort study used data collected between January 6, 1996, and February 28, 2018, in the Study of Women's Health Across the Nation cohort study, an ongoing, US-based, multicenter, longitudinal study of the MT in diverse ambulatory women. The study included 1690 midlife women in premenopause or early perimenopause at study inception (who have since transitioned to postmenopause) who did not have type 2 diabetes before the MT and who did not take bone-beneficial medications before the MT. Start of the MT was defined as the first visit in late perimenopause (or first postmenopausal visit if participants transitioned directly from premenopause or early perimenopause to postmenopause). Mean (SD) follow-up was 12 (6) years. Statistical analysis was conducted from January to May 2022.

Exposure

Proportion of visits before the MT that women had prediabetes (fasting glucose, 100-125 mg/dL [to convert to millimoles per liter, multiply by 0.0555]), with values ranging from 0 (prediabetes at no visits) to 1 (prediabetes at all visits).

Main Outcomes and Measures

Time to first fracture after the start of the MT, with censoring at first diagnosis of type 2 diabetes, initiation of bone-beneficial medication, or last follow-up. Cox proportional hazards regression was used to examine the association (before and after adjustment for bone mineral density) of prediabetes before the MT with fracture during the MT and after menopause.

Results

This analysis included 1690 women (mean [SD] age, 49.7 [3.1] years; 437 Black women [25.9%], 197 Chinese women [11.7%], 215 Japanese women [12.7%], and 841 White women [49.8%]; mean [SD] body mass index [BMI] at the start of the MT, 27.6 [6.6]). A total of 225 women (13.3%) had prediabetes at 1 or more study visits before the MT, and 1465 women (86.7%) did not have prediabetes before the MT. Of the 225 women with prediabetes, 25 (11.1%) sustained a fracture, while 111 of the 1465 women without prediabetes (7.6%) sustained a fracture. After adjustment for age, BMI, and cigarette use at the start of the MT; fracture before the MT; use of bone-detrimental medications; race and ethnicity; and study site, prediabetes before the MT was associated with more subsequent fractures (hazard ratio for fracture with prediabetes at all vs no pre-MT visits, 2.20 [95% CI, 1.11-4.37]; P = .02). This association was essentially unchanged after controlling for BMD at the start of the MT.

Conclusions and Relevance

This cohort study of midlife women suggests that prediabetes was associated with risk of fracture. Future research should determine whether treating prediabetes reduces fracture risk.

Statin use in patients with type 2 diabetes has lower risk of hip fractures: A Taiwan national population-based study

AIMS

Type 2 diabetes mellitus (T2DM) frequently co-exists with osteoporosis and dyslipidemia. Statins have been commonly used in the treatment of dyslipidemia. Recent studies have indicated a therapeutic role of statins in decreasing the risk of osteoporosis and fractures, but conflicting results have been reported. This study investigated the association between statin use and hip fracture (HFx) risk among T2DM patients.

MATERIALS AND METHODS

A retrospective Taiwan population-based propensity-matched cohort study was performed using the Diabetes Mellitus Health Database from Taiwan National Health Insurance Research Database. Patients with newly diagnosed with T2DM between 2010 and 2014 were identified. Patients who previously used statins and had ever suffered HFx before the index date were excluded. HFx that occurred from 2010 to 2019 was collected to compute the cumulative rate of HFx. Hazard ratios (HRs) were calculated for the HFx risk according to the use or non-use of statins. To evaluate the dose-effect relationship of statins, sensitivity analyses were conducted.

RESULTS

After propensity score matching for age and sex, 188,588 patients were identified as statin users and non-statin users. Statin use after T2DM diagnosis was associated with a decreased HFx risk with an adjusted HR (aHR) of 0.69 (P < 0.001). A dose-effect relationship was identified. The aHRs for developing HFx were 1.29, 0.67, and 0.36 for patients who used 28-174, 175-447, and >447 cumulative defined daily doses of statins, respectively (P < 0.001).

CONCLUSIONS

Statin use in adults with T2DM showed a lower risk of HFx by demonstrating a dose-response relationship.

Changes in Bone Turnover Markers after Roux-en-Y Gastric Bypass Versus Sleeve Gastrectomy: a Systematic Review and Meta-Analysis

This systematic review and meta-analysis was performed to compare the alterations in bone turnover markers between SG and RYGB. A literature search was conducted in PubMed, Medline, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases to find the studies. There was significant less increment in osteocalcin [WMD =  - 5.98, 95% CI (- 9.30, - 2.47) P < 0.01] and parathyroid hormone (PTH) [WMD =  - 9.59, 95% CI (- 15.02, - 4.16) P < 0.01] in the SG group compared to the RYGB group. No significant differences were seen in change of C-terminal telopeptide of type I collagen (CTX), N-terminal propeptide of type I collagen (PINP), Ca, and 25(OH)-D between SG and RYGB groups. According to our meta-analysis, bone formation markers appear to have more increment following RYGB than SG. This observation is accompanied by a larger increase in PTH after RYGB patients compared to SG patients. PROSPERO: CRD42022308985.

Assessment and treatment of osteoporosis and fractures in type 2 diabetes

There is substantial, and growing, evidence that type 2 diabetes (T2D) is associated with skeletal fragility, despite often preserved bone mineral density. As post-fracture outcomes, including mortality, are worse in people with T2D, bone management should be carefully considered in this highly vulnerable group. However, current fracture risk calculators inadequately predict fracture risk in T2D, and dedicated randomised controlled trials identifying optimal management in patients with T2D are lacking, raising questions about the ideal assessment and treatment of bone health in these people. We synthesise the current literature on evaluating bone measurements in T2D and summarise the evidence for safety and efficacy of both T2D and anti-osteoporosis medications in relation to bone health in these patients.

Bone Response to Weight Loss Following Bariatric Surgery

Obesity is a global health challenge that warrants effective treatments to avoid its multiple comorbidities. Bariatric surgery, a cornerstone treatment to control bodyweight excess and relieve the health-related burdens of obesity, can promote accelerated bone loss and affect skeletal strength, particularly after malabsorptive and mixed surgical procedures, and probably after restrictive surgeries. The increase in bone resorption markers occurs early and persist for up to 12 months or longer after bariatric surgery, while bone formation markers increase but to a lesser extent, suggesting a potential uncoupling process between resorption and formation. The skeletal response to bariatric surgery, as investigated by dual-energy X-ray absorptiometry (DXA), has shown significant loss in bone mineral density (BMD) at the hip with less consistent results for the lumbar spine. Supporting DXA studies, analyses by high-resolution peripheral quantitative computed tomography (HR-pQCT) showed lower cortical density and thickness, higher cortical porosity, and lower trabecular density and number for up to 5 years after bariatric surgery. These alterations translate into an increased risk of fall injury, which contributes to increase the fracture risk in patients who have been subjected to bariatric surgery procedures. As bone deterioration continues for years following bariatric surgery, the fracture risk does not seem to be dependent on acute weight loss but, rather, is a chronic condition with an increasing impact over time. Among the post-bariatric surgery mechanisms that have been claimed to act globally on bone health, there is evidence that micro- and macro-nutrient malabsorptive factors, mechanical unloading and changes in molecules partaking in the crosstalk between adipose tissue, bone and muscle may play a determining role. Given these circumstances, it is conceivable that bone health should be adequately investigated in candidates to bariatric surgery through bone-specific work-up and dedicated postsurgical follow-up. Specific protocols of nutrients supplementation, motor activity, structured rehabilitative programs and, when needed, targeted therapeutic strategies should be deemed as an integral part of post-bariatric surgery clinical support.

Obesity and Bone Loss at Menopause: The Role of Sclerostin

Background. Peripheral fat tissue is known to positively influence bone health. However, evidence exists that the risk of non-vertebral fractures can be increased in postmenopausal women with obesity as compared to healthy controls. The role of sclerostin, the SOST gene protein product, and body composition in this condition is unknown. Methods. We studied 28 severely obese premenopausal (age, 44.7 ± 3.9 years; BMI, 46.0 ± 4.2 kg/m²) and 28 BMI-matched post-menopausal women (age, 55.5 ± 3.8 years; BMI, 46.1 ± 4.8 kg/m²) thorough analysis of bone density (BMD) and body composition by dual X-ray absorptiometry (DXA), bone turnover markers, sclerostin serum concentration, glucose metabolism, and a panel of hormones relating to bone health. Results. Postmenopausal women harbored increased levels of the bone turnover markers CTX and NTX, while sclerostin levels were non-significantly higher as compared to premenopausal women. There were no differences in somatotroph, thyroid and adrenal hormone across menopause. Values of lumbar spine BMD were comparable between groups. By contrast, menopause was associated with lower BMD values at the hip (p < 0.001), femoral neck (p < 0.0001), and total skeleton (p < 0.005). In multivariate regression analysis, sclerostin was the strongest predictor of lumbar spine BMD (p < 0.01), while menopausal status significantly predicted BMD at total hip (p < 0.01), femoral neck (p < 0.001) and total body (p < 0.05). Finally, lean body mass emerged as the strongest predictor of total body BMD (p < 0.01). Conclusions. Our findings suggest a protective effect of obesity on lumbar spine and total body BMD at menopause possibly through mechanisms relating to lean body mass. Given the mild difference in sclerostin levels between pre- and postmenopausal women, its potential actions in obesity require further investigation.

Management of bone fragility in type 2 diabetes: Perspective from an interdisciplinary expert panel

AIM

Bone fragility is increasingly recognized as a relevant complication of type 2 diabetes (T2D) and diabetic patients with fragility fractures have higher mortality rates than non diabetic individuals or diabetic patients without fractures. However, current diagnostic approaches for fracture risk stratification, such as bone mineral density measurement or the use of risk assessment algorithms, largely underestimate fracture risk in T2D patients. A multidisciplinary expert panel was established in order to in order to formulate clinical consensus recommendations on bone health assessment and management of fracture risk in patients with T2D.

DATA SYNTHESIS

The following key questions were addressed: a) which are the risk factors for bone fragility in T2D?, b) which diagnostic procedures can be currently used to stratify fracture risk in T2D patients?, c) which are the effects of antidiabetic treatments on bone?, and d) how to prevent and treat bone fragility in T2D patients? Based on the available data members of this panel suggest that the stratification of fracture risk in patients with diabetes should firstly rely on the presence of a previous fragility fracture and on the individual risk profile, with the inclusion of T2D-specific risk factors (namely T2D duration above 10 yrs, presence of chronic T2D complications, use of insulin or thiazolidinediones and persistent HbA1c levels above 8% for at least 1 year). Two independent diagnostic approaches were then suggested in the presence or the absence of a prevalent fragility fracture, respectively.

CONCLUSIONS

Clinical trials in T2D patients at risk for fragility fractures are needed to determine the efficacy and safety of available antiresorptive and anabolic agents in this specific setting.

Identification and Functional Characterization of Metabolites for Bone Mass in Peri- and Postmenopausal Chinese Women

CONTEXT

Although metabolic profiles appear to play an important role in menopausal bone loss, the functional mechanisms by which metabolites influence bone mineral density (BMD) during menopause are largely unknown.

OBJECTIVE

We aimed to systematically identify metabolites associated with BMD variation and their potential functional mechanisms in peri- and postmenopausal women.

DESIGN AND METHODS

We performed serum metabolomic profiling and whole-genome sequencing for 517 perimenopausal (16%) and early postmenopausal (84%) women aged 41 to 64 years in this cross-sectional study. Partial least squares regression and general linear regression analysis were applied to identify BMD-associated metabolites, and weighted gene co-expression network analysis was performed to construct co-functional metabolite modules. Furthermore, we performed Mendelian randomization analysis to identify causal relationships between BMD-associated metabolites and BMD variation. Finally, we explored the effects of a novel prominent BMD-associated metabolite on bone metabolism through both in vivo/in vitro experiments.

RESULTS

Twenty metabolites and a co-functional metabolite module (consisting of fatty acids) were significantly associated with BMD variation. We found dodecanoic acid (DA), within the identified module causally decreased total hip BMD. Subsequently, the in vivo experiments might support that dietary supplementation with DA could promote bone loss, as well as increase the osteoblast and osteoclast numbers in normal/ovariectomized mice. Dodecanoic acid treatment differentially promoted osteoblast and osteoclast differentiation, especially for osteoclast differentiation at higher concentrations in vitro (eg,10, 100 μM).

CONCLUSIONS

This study sheds light on metabolomic profiles associated with postmenopausal osteoporosis risk, highlighting the potential importance of fatty acids, as exemplified by DA, in regulating BMD.

Diabetes and Osteoporosis: Part II, Clinical Management

Diabetes-induced osteoporosis is characterized by an increase in fracture risk. FRAX, the most widely used tool, underestimates the risk of fracture in both type 1 and type 2 diabetes. Specific adjustments to FRAX can help to better identify patients with diabetes at increased risk of fracture and select those at high fracture risk for treatment. Although clinical trial data are limited, the available evidence indicates that the presence of diabetes does not alter antiosteoporotic treatment response in patients with diabetes.

Increasing fasting glucose and fasting insulin associated with elevated bone mineral density-evidence from cross-sectional and MR studies

We performed a cross-sectional study using the National Health Examination and Nutrition Survey (NHANES) data and a Mendelian randomisation (MR) study using the GWAS summary statistics from European populations. The T2D-related indices (fasting plasma glucose (FPG), fasting insulin (FI), and insulin resistance (IR)) were found to associate with elevated bone mineral density (BMD).

INTRODUCTION

The known associations amongst FPG, FI, IR, and BMD remain inconsistent. This study aims to explore the abovementioned associations by using cross-sectional and MR designs.

METHODS

Data from adults aged ≥ 20 years (n = 7170) in four rounds of the U.S. NHANES (2005-2010 and 2013-2014) were analysed in this cross-sectional study. Multiple linear and logistic regression models were used for statistical analyses. A two-sample MR study was performed using the genome-wide association study summary statistics obtained from the Meta-analyses of Glucose and Insulin-related traits Consortium (n = 108,557) and Genetic Factors for Osteoporosis Consortium (n = 32,735) to examine the causality of the FI-BMD association.

RESULTS

Multiple linear regression revealed that FPG was positively associated with the BMDs at the hip, femur neck, and 1st lumbar spine (L1). Multiple logistic regressions revealed that FPG levels were associated with elevated BMDs at the hip and L1, and FI and IR levels were associated with elevated BMD at the hip. Patients with type 2 diabetes had higher hip BMD than those without diabetes. In the MR study, the lumbar spine BMD increased by 0.49 g/cm² (95% confidence interval: 0.01, 0.97) in response to per unit increase in log-transformed FI.

CONCLUSION

Findings from our cross-sectional and MR studies revealed the associations between the studied diabetic indices and BMD measurements in the US and European adults.

Diabetes and Bone Fragility

Diabetes is a highly prevalent disease with complications that impact most bodily systems. However, the impact of diabetes on bone health is frequently ignored or underestimated. Both type 1 (T1D) and type 2 diabetes (T2D) are associated with a higher risk of fractures, albeit through different mechanisms. T1D is characterized by near total insulinopenia, which affects the anabolic tone of bone and results in reduced bone mineral density (BMD). Meanwhile, patients with T2D have normal or high BMD, but carry an increased risk of fractures due to alterations of bone microarchitecture and a local humoral environment that stimulates osteoclast activity. Chronic hyperglycemia induces non-enzymatic glycation of collagen in both types of diabetes. Epidemiological evidence confirms a largely increased fracture risk in T1D and T2D, but also that it can be substantially reduced by opportune monitoring of fracture risk and appropriate treatment of both diabetes itself and osteopenia or osteoporosis if they are present. In this review, we summarize the mechanistic, epidemiological, and clinical evidence that links diabetes and bone fragility, and describe the impact of available diabetes treatments on bone health.

Fasting glucose level and the risk of incident osteoporosis in the Koreans

PURPOSE/INTRODUCTION

Conflicting results have been published regarding the effect of abnormal glucose metabolism on osteoporosis (AGM). Fasting glucose is a reliable indicator for abnormal glucose metabolism. Therefore, the aim of present study is to identify the association of fasting glucose level with the risk of incident osteoporosis.

METHODS

In a cohort of 59,936 men and 36,690 women (mean age of 63.9 ± 7.1 years) registered in national health insurance database, we assessed the risk of incident osteoporosis according to the quartile levels of baseline fasting glucose (quartile 1: <88 mg/dL, quartile 2: 88-96 mg/dL, quartile 3: 97-107 mg/dL and quartile 4: ≥108 mg/dL) and glycemic status categorized into normal, impaired fasting glucose (IFG) and diabetes mellitus (DM). Multivariate Cox-proportional hazard model was used in calculating adjusted hazard ratios (HRs) and 95% confidence interval (CI) for incident osteoporosis (adjusted HRs [95% CI]).

RESULTS

Compared with first quartile (reference), the risk of osteoporosis significantly decreased above the fourth quartile in men (second quartile: 1.04 [0.91-1.18], third quartile: 0.88 (0.76-1.00) and fourth quartile: 0.80 [0.70-0.92]) and above third quartile in women (second quartile: 0.95 [0.90-1.01], third quartile: 0.91 [0.86-0.97] and fourth quartile: 0.82 [0.77-0.88]). The risk of osteoporosis was less associated with IFG (men: 0.84 [0.76-0.94] and women: 0.93 [0.89-0.98]) and DM (men: 0.77 [0.65-0.91] and women: 0.75 [0.69-0.81]) than normal glucose group in both men and women.

CONCLUSION

Our results suggest that elevated fasting glucose potentially associated with the decreased risk of osteoporosis.

MINI-ABSTRACT

This retrospective study investigated the association between fasting glucose level and incidence of osteoporosis. Our findings indicate that elevated fasting glucose is significantly associated with the decreased risk of osteoporosis.

Folate and Vitamin B-12 Status Is Associated With Bone Mineral Density and Hip Strength of Postmenopausal Chinese-Singaporean Women

The role of micronutrients such as folate and vitamin B‐12 in bone quality has been widely studied with conflicting results. Ethnicity seems to play a large role on nutrient intake, as diet varies across cultures. In this study, we examined the relationships of BMD, proximal femur strength, and bone resorption with plasma folate and vitamin B‐12 in a cohort of 93 healthy postmenopausal women of Chinese‐Singaporean descent. The parameters examined were areal (aBMD) and volumetric BMD (vBMD) of the proximal femur and the third lumbar vertebra (L3), total body aBMD, proximal femur bending, compressive and impact strength indices (composite strength indices) and circulating levels of C‐telopeptide of type I collagen. Eighteen participants (19.4%) had aBMD in the osteoporotic range (osteoporosis group), 59 (63.4%) in the osteopenic range (osteopenia group), and the remaining 16 (17.2%) in the normal range (normal BMD group). Circulating folate levels were significantly higher in the normal BMD group compared with the osteoporosis group. Using linear regression analysis, we found that overall, aBMD and vBMD are positively associated with folate concentrations, whereas composite strength indices were positively associated with vitamin B‐12 concentrations. These findings support the existing literature and suggest a link between levels of circulating folate/vitamin B‐12 and BMD/bone strength in the cohort examined. Further investigation is needed to examine if individuals with inadequate circulating levels of these nutrients could decrease their risk for fragility fractures through better nutrition or vitamin supplementation. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Prediction of mortality at one year after surgery for pertrochanteric fracture in the elderly via a Bayesian belief network

BACKGROUND

Pertrochanteric fractures in the elderly are common and associated with considerable mortality and disability. However, the predictors of the fracture mortality have been somewhat controversial. The aim of this study was to use univariate, multivariate analyses and a Bayesian belief network (BBN) model, which are graphic and intuitive to the clinician, to understand of the prognosis of pertrochanteric fractures.

METHODS

Records of patients undergoing surgery at our hospital between January 2013 and June 2018 were retrospectively reviewed. Univariate and multivariate regression as well as a machine-learned BBN model were used to estimate mortality at one year after surgery for pertrochanteric fracture in the elderly.

RESULTS

Complete data were available for 448 surgically treated patients who were followed up for 12 months (age ≥60 years). Multivariate regression analysis revealed that hypertension, diabetes mellitus, chronic obstructive pulmonary disease, albumin, serum potassium, blood urea nitrogen and blood lactate were independent risk factors for death in surgical treatment patients (P < 0.05). First-degree predictors of mortality following surgery were established: the number of comorbid diseases, serum albumin, blood lactate and blood urea nitrogen. Following cross-validation, the area under the ROC curve was 0.85 (95% CI: 0.76-0.91) for the one-year probability of postoperative mortality.

CONCLUSION

We believe cohesive models such as the Bayesian belief network can be useful as clinical decision-support tools and provide clinicians with information to the treatment of old pertrochanteric fracture. This method warrants further development and must be externally validated in other patient populations.

Bone turnover and bone mineral density in old persons with type 2 diabetes

AIMS

To understand the paradox of an increased fracture risk despite increased bone mineral density (BMD) in persons with type 2 diabetes (DM2).

PATIENTS AND METHODS

We studied 80 old persons with DM2. Mineral metabolism, parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), bone turnover - osteocalcin, procollagen type 1 N-terminal propeptide (P1NP) and C-terminal telopeptide of type 1 collagen (CTX) - were measured and BMD was assessed at the lumbar spine (LS) and femoral neck (FN). Data was analyzed with the Statistical Package for the Social Sciences Program.

RESULTS

Low levels of 25OHD (84%) and high values of PTH (20%) were found. Osteocalcin was directly related to CTX, p < 0.001, with increased bone formation and increased BMD (z-score) at LS and FN. PTH was directly related to osteocalcin and CTX and inversely related to BMD at the FN, p < 0.05. Patients with dyslipidemia presented higher P1NP, p < 0.05 and patients with hypertension presented higher BMD at LS and FN, p < 0.01.

CONCLUSION

Old type 2 diabetics present increased bone formation, PTH-driven. Low grade secondary hyperparathyroidism may explain the paradox of an increased fracture risk despite increased BMD.

Bone Health During the Menopause Transition and Beyond

The menopause transition is a critical period for bone health, with rapid losses in bone mass and strength occurring in a 3-year window bracketing the date of the final menstrual period. Declines in bone mass are accompanied by deleterious changes in bone macrostructure and microarchitecture, which may be captured by changes in composite strength indices and indices of trabecular thickness and connectivity. The onset of the rapid bone loss phase is preceded by changes in sex steroid hormones and increases in markers of bone resorption, measurements of which may be clinically useful in predicting the onset of the rapid loss phase and in identifying the women who will lose the most bone strength over the menopause transition.

Type 2 Diabetes in Relation to Hip Bone Density, Area, and Bone Turnover in Swedish Men and Women: A Cross-Sectional Study

Men and women with type 2 diabetes mellitus (T2DM) have higher risk of hip fracture, but the mechanisms are not fully understood. We aimed to investigate how T2DM, glucose, and insulin were associated with femoral bone mineral density (BMD), bone mineral area (BMA), and bone turnover markers. We used two cross-sectional cohorts: the Uppsala Longitudinal Study of Adult Men (ULSAM, n = 452, mean age 82 years) and the Swedish Mammography Cohort Clinical (SMCC, n = 4713, mean age 68 years). We identified men and women with normal fasting glucose (NFG), impaired fasting plasma glucose (IFG), and T2DM. BMD and BMA at the total hip and femoral shaft were measured using dual energy X-ray absorptiometry (DXA). Bone turnover markers; CrossLaps and osteocalcin were measured in women. Linear regression models were applied. Men and women showed a progressively higher BMD following the clinical cutoffs of fasting glucose from NFG to IFG to T2DM. In contrast, there was a progressively lower BMA. Men and women with T2DM, compared to those with NFG, had lower BMA at the total hip (- 1.7%; 95% CI - 3.2, - 0.2 and - 1.0%; 95% CI - 1.6, - 0.4) and the femoral shaft (- 2.0%; 95% CI - 3.5, - 0.4 and - 0.6%; 95% CI - 1.2, - 0.01), respectively. T2DM was associated with lower concentrations of CrossLaps (- 8.1%; 95% CI - 12.7, - 3.6) and osteocalcin (- 15.2%; 95% CI - 19.0, - 11.2). These cross-sectional results indicate that those with T2DM have smaller bone area and lower bone turnover, which could increase the risk of hip fracture.

The positive association of total protein intake with femoral neck strength (KNHANES IV)

Data gathered from a nationally representative cohort demonstrate that higher dietary protein intake was positively associated with the composite indices of femoral neck strength in both men and women, suggesting that higher protein intake may contribute to lower risk of hip fracture through the improvement of bone strength.

INTRODUCTION

Despite the general belief that higher protein intake may be helpful for bone homeostasis, its impact on human bone health is still debated. Furthermore, the association of dietary protein intake with femoral neck (FN) strength, which can predict fracture risk independently of bone mineral density (BMD), has not been thoroughly studied.

METHODS

This is a population-based, cross-sectional study from Korea National Health and Nutrition Examination Surveys, including 592 men aged 50 years or older and 590 postmenopausal women. The composite indices of FN strength, such as the compression strength index (CSI), bending strength index (BSI), and impact strength index (ISI), were generated by combining BMD, body weight, and height with the femoral axis length and width, which were measured by dual-energy X-ray absorptiometry.

RESULTS

After adjustment for confounders, total protein intake (g/kg/day) positively correlated with all three FN composite indices in both genders (P = 0.006 to 0.035), except for BSI showing marginal significance in postmenopausal women (P = 0.093). Consistently, compared with subjects in lowest total protein intake quartile, those in the highest quartile showed markedly higher CSI, BSI, and ISI values (P = 0.043 to < 0.001), with a dose-response manner across increasing total protein intake quartile categories in both men and women (P for trend = 0.028 to < 0.001).

CONCLUSIONS

These findings provide the clinical evidence that higher dietary protein intake can play a beneficial role on bone health through the increase of FN strength relative to load in adults.

Association of Insulin Resistance with Bone Strength and Bone Turnover in Menopausal Chinese-Singaporean Women without Diabetes

Insulin resistance (IR) is accompanied by increased areal or volumetric bone mineral density (aBMD or vBMD), but also higher fracture risk. Meanwhile, imbalances in bone health biomarkers affect insulin production. This study investigates the effect of IR on proximal femur and lumbar spine BMD, femoral neck bending, compressive and impact strength indices (Composite Strength Indices) and circulating levels of parathyroid hormone (PTH), C-telopeptide of Type I collagen (CTx-1) and 25(OH) Vitamin D₃, in a cohort of 97 healthy, non-obese, menopausal Chinese-Singaporean women. Lumbar spine aBMD was inversely associated with IR and dependent on lean body mass (LBM) and age. No such associations were found for vBMD of the third lumbar vertebra, aBMD and vBMD of the proximal femur, or circulating levels of PTH, CTx-1 and 25(OH) Vitamin D₃. Composite Strength Indices were inversely associated with IR and independent of LBM, but after adjusting for fat mass and age, this association remained valid only for the impact strength index. Composite Strength Indices were significantly lower in participants with a high degree of IR. Our findings on IR and Composite Strength Indices relationships were in agreement with previous studies on different cohorts, but those on IR and BMD associations were not.

Epidemiology and correlates of osteoporotic fractures among type 2 diabetic patients

This study analyzed data on 87,224 osteoporotic patients with up to 18 years of computerized medical history. Patients with osteoporosis and type 2 diabetes had higher bone density yet more fractures than non-diabetic osteoporotic patients. Fracture incidence among the diabetic patients was associated with retinopathy and cardiovascular disease, but not with diabetes duration.

PURPOSE

Little is known about the association between type 2 diabetes mellitus (T2DM) and fragility fractures or the mechanism(s) involved. We examined fracture correlates among T2DM patients with osteoporosis.

METHODS

We used electronic health records of an osteoporosis (OP) registry cross-linked with a diabetes registry of a large payer provider healthcare organization in Israel. A cross-sectional analysis compared osteoporosis patients with and without T2DM, and a longitudinal Cox proportional hazard regression was used to identify incident fracture correlates.

RESULTS

As of December 2015 a total of 87,224 current OP patients were identified, of whom 15,700 (18%) had T2DM. The T2DM OP patients were characterized by older age (mean 74.6 vs. 69.5), more males (20.3 vs. 14.0%), and a higher rate of chronic comorbidities compared to OP without diabetes. All major OP fractures (hip, spine, humerus, and forearm) were significantly more prevalent among T2DM OP patients (44 vs. 32%), with an overall age-standardized ratio of 1.22 (95% CI 1.19 to 1.25) and 1.15 (95% CI 1.10 to 1.21) for females and males respectively. The average T-scores were higher (femur neck - 1.8 vs. - 1.9, total hip - 1.2 vs. - 1.6, and vertebrae - 1.3 vs. - 1.7) for the T2DM OP patients compared to the non-T2DM OP patients. Among women with coexisting T2DM and osteoporosis (n = 10,812), fracture incidence was significantly associated with retinopathy (HR = 1.24, 95% CI 1.05 to 1.47) and cardiovascular disease (HR = 1.22, 95% CI 1.10 to 1.36) after controlling for age, bone mineral density T-score, rheumatoid arthritis, glucocorticoids, alcohol, and smoking).

CONCLUSION

This large population-based study confirms the higher fracture risk of osteoporotic patients with T2DM, as compared to osteoporotic patients without T2DM, despite higher bone mineral density levels. The presence of micro- and macrovascular disease appears to increase this risk.

The effect of insulin on bone mineral density among women with type 2 diabetes: a SWAN Pharmacoepidemiology study

This was a longitudinal study examining the effects of insulin use on bone mineral density loss. Insulin use was found to be associated with greater bone mineral density loss at the femoral neck among women with diabetes mellitus.

INTRODUCTION

Women with diabetes mellitus (DM) have higher bone mineral density (BMD) and experience slower BMD loss but have an increased risk of fracture. The data regarding the effect of insulin treatment on BMD remains conflicted. We examined the impact of insulin initiation on BMD.

METHODS

We investigated the annual changes in BMD associated with the new use of insulin among women with DM in the Study of Women's Health Across the Nation (SWAN). Propensity score (PS) matching, which is a statistical method that helps balance the baseline characteristics of women who did and did not initiate insulin, was used. Covariates with a potential impact on bone health were included in all models. Mixed model regression was used to test the change in BMD between the two groups. Median follow-up time was 5.4 years.

RESULTS

The cohort consisted of 110 women, mean age, 53.6 years; 49% white and 51% black. Women using insulin (n = 55) were similar on most relevant characteristics to the 55 not using insulin. Median diabetes duration for the user group was 10 vs. 5.0 years for the non-user group. There was a greater loss of BMD at the femoral neck among insulin users (- 1.1%) vs non-users (- 0.77%) (p = 0.04). There were no differences in BMD loss at the spine - 0.30% vs - 0.32% (p = 0.85) or at the total hip - 0.31% vs - 0.25 (p = 0.71), respectively.

CONCLUSIONS

Women with T2DM who initiated insulin experienced a more rapid BMD loss at the femoral neck as compared to women who did use insulin.

Association of Nonalcoholic Fatty Liver Disease With Osteoporotic Fractures: A Cross-Sectional Retrospective Study of Chinese Individuals

Objective: Nonalcoholic fatty liver disease (NAFLD) is related to several inflammatory or metabolic diseases. However, findings of previous studies investigating the association between NAFLD and BMD are inconsistent. Only one study reported a potential association between NAFLD and osteoporotic fracture. This study investigated whether NAFLD in older participants (>55 years) was associated with osteoporotic fracture risk. Materials and Methods: This cross-sectional, observational study included 2,695 participants (35.7% men, 614 cases of NAFLD, and 383 fractures). Standardized questionnaires, laboratory tests, and physical and ultrasonic examinations were completed. Results: After adjusting for various factors including serum triglycerides (TG), high-density cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), multivariate logistic regression models revealed a marginal association between NAFLD and osteoporotic fracture risk in men (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.06-3.27; P = 0.030) but no association in women (OR, 1.05; 95% CI, 0.74-1.48; P = 0.800). Further stratified analyses showed a significant association between NAFLD and osteoporotic fracture risk in men without high TG, low HDL-C, and high LDL-C. Conclusions: There was a significant association between NAFLD and osteoporotic fracture risk in older Chinese men, particularly men without dyslipidemia.

Association of insulin resistance with near peak bone mass in the femur and lumbar spine of Korean adults aged 25-35: The Korean National Health and Nutrition Examination Survey 2008-2010

Objective

This study aimed to evaluate the relationship between insulin resistance and the bone mineral density (BMD) of femur and lumbar spine in Korean adults who are expected to exhibit near peak bone mass.

Methods

Data from the Korean National Health and Nutrition Examination Survey 2008–2010 were analyzed. A total of 2,750 participants aged 25−35 years were included. Insulin resistance was assessed using a homeostatic model assessment of insulin resistance (HOMA-IR) and serum fasting insulin.

Results

In a multivariate linear regression analysis, the HOMA-IR was significantly inversely associated with the BMD of the total hip (TH, β = −0.052, P = 0.002), femoral neck (FN, β = −0.072, P<0.001), femoral trochanter (FTr, β = −0.055, P = 0.003), femoral intertrochanter (FITr, β = −0.041, P = 0.015), and lumbar spine (LS, β = −0.063, P = 0.001) among all study subjects after adjustment for gender, age, height, weight, whole body fat mass percentage, systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, vitamin D, smoking, alcohol intake, physical activity, education level, and household income in both genders as well as labor, the use of oral contraceptives, and age at menarche in females. The serum fasting insulin was significantly inversely associated with the BMD of the TH (β = −0.055, P = 0.001), FN (β = −0.072, P<0.001), FTr (β = −0.055, P = 0.003), FITr (β = −0.045, P = 0.009), and LS (β = −0.064, P = 0.001) among all subjects in a multivariate linear regression analysis.

Conclusion

Our results suggest that insulin resistance may be independently and inversely associated with the near peak bone mass of the femur and lumbar spine.

Association between obesity and femoral neck strength according to age, sex, and fat distribution

Indicators of total and abdominal obesity were negatively associated with femoral neck strength indices. There are age-, sex-, and fat distribution-specific differences in the magnitude of these associations. These suggested that indicators of obesity with different magnitude according to age, sex, and fat distribution associated with poor bone health.

INTRODUCTION

Fat regulates bone metabolism, but the associations of total and abdominal obesity with bone health are inconsistent. We investigated the association between indicators of obesity and composite indices of femoral neck (FN) strength reflecting the risk of hip fracture.

METHODS

This population-based cross-sectional study examined data from the Korea National Health and Nutrition Examination Surveys. Participants were divided into groups according to age (25-49/≥50 years) and sex. We examined total fat mass (TFM) and percentage fat mass (pFM) as indicators of total obesity and truncal fat mass (TrFM) as an indicator of abdominal obesity. We calculated the composite indices of FN strength and anthropometric clinical indicators of abdominal obesity.

RESULTS

TFM, pFM, and TrFM were negatively associated with the composite indices, irrespective of age and sex (P < 0.001-0.005). Most anthropometric clinical indicators of abdominal obesity showed negative associations with the composite indices regardless of age and sex (P < 0.001-0.048), except for women aged 25-49 years. In men, magnitudes of the negative contributions of TFM to the composite indices were significantly stronger at age 25-49 years than at age ≥50 years. Magnitudes of negative associations of TFM with the composite indices were greater in men than in women. TrFM had a more detrimental effect than TFM on FN strength in men aged 25-49 years and in women of both ages.

CONCLUSION

Indicators of total and abdominal obesity negatively associated with FN strength, and magnitudes of their effects on bone health differed according to age, sex, and fat distribution.

Non-alcoholic fatty liver disease connections with fat-free tissues: A focus on bone and skeletal muscle

The estimates of global incidence and prevalence of non-alcoholic fatty liver disease (NAFLD) are worrisome, due to the parallel burden of obesity and its metabolic complications. Indeed, excess adiposity and insulin resistance represent two of the major risk factors for NAFLD; interestingly, in the last years a growing body of evidence tended to support a novel mechanistic perspective, in which the liver is at the center of a complex interplay involving organs and systems, other than adipose tissue and glucose homeostasis. Bone and the skeletal muscle are fat- free tissues which appeared to be independently associated with NAFLD in several cross-sectional studies. The deterioration of bone mineral density and lean body mass, leading to osteoporosis and sarcopenia, respectively, are age-related processes. The prevalence of NAFLD also increases with age. Beyond physiological aging, the three conditions share some common underlying mechanisms, and their elucidations could be of paramount importance to design more effective treatment strategies for the management of NAFLD. In this review, we provide an overview on epidemiological data as well as on potential contributors to the connections of NAFLD with bone and skeletal muscle.

Diabetes and Bone Disease

The World Health Organization estimates that diabetes mellitus occurs in more than 415 million people; this number could double by the year 2040. Epidemiologic data have shown that the skeletal system may be a target of diabetes-mediated damage, leading to the development of diabetes-induced osteoporosis. T1D and T2D have been associated with an increased risk of fracture. Bone mineral density and fracture risk prediction tools developed for the general population capture some of the risk associated with diabetes. Recent adaptations to these tools have improved their efficacy in patients with diabetes.

DXA-Based Measurements in Diabetes: Can They Predict Fracture Risk?

In the absence of a fragility fracture, osteoporosis is usually diagnosed from bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA). Osteoporosis is an increasingly prevalent disease, as is diabetes [in particular type 2 diabetes (T2D)], in part due to aging populations worldwide. It has been suggested that an increased risk of fracture may be another complication ensuing from longstanding diabetes. The purpose of this review is to concentrate on skeletal parameters and techniques readily available from DXA scanning, and their utility in routine clinical practice for predicting fracture risk. In addition to BMD, other applications and measures from DXA include trabecular bone score (TBS), skeletal geometry and DXA-based finite-element analysis, vertebral fracture assessment, and body composition. In type 1 diabetes (T1D), BMD and FRAX^R (when secondary osteoporosis is included without BMD) only partially account for the excess risk of fracture in T1D. Consistent data exist to show that BMD and FRAX^R can be used to stratify fracture risk in T2D, but do not account for the increased risk of fracture. However, several adjustments to the FRAX score can be made as proxies for T2D to inform the use of FRAX by primary care practitioners. Examples include using the rheumatoid arthritis input (as a proxy for T2D), lumbar spine TBS (to adjust FRAX probability) or an altered hip T-score (lowered by 0.5 units). These adjustments can improve fracture risk prediction in T2D and help to avoid systematically underestimating the risk of osteoporosis-related fractures in those with diabetes.

Obesity is a concern for bone health with aging

Accumulating evidence supports a complex relationship between adiposity and osteoporosis in overweight/obese individuals, with local interactions and endocrine regulation by adipose tissue on bone metabolism and fracture risk in elderly populations. This review was conducted to summarize existing evidence to test the hypothesis that obesity is a risk factor for bone health in aging individuals. Mechanisms by which obesity adversely affects bone health are believed to be multiple, such as an alteration of bone-regulating hormones, inflammation, oxidative stress, the endocannabinoid system, that affect bone cell metabolism are discussed. In addition, evidence on the effect of fat mass and distribution on bone mass and quality is reviewed together with findings relating energy and fat intake with bone health. In summary, studies indicate that the positive effects of body weight on bone mineral density cannot counteract the detrimental effects of obesity on bone quality. However, the exact mechanism underlying bone deterioration in the obese is not clear yet and further research is required to elucidate the effect of adipose depots on bone and fracture risk in the obese population.

Higher serum ferritin level and lower femur neck strength in women at the stage of bone loss (≥ 45 years of age): The Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV)

PURPOSE

Despite the clear effect of iron on bone metabolism, most clinical studies related to bone health have only focused on bone mineral density (BMD). In the present study, we investigated the relationship between serum ferritin and composite indices of femur neck strength via a population-based, cross-sectional study using the Korea National Health and Nutrition Examination Survey (KNHANES).

METHODS

Our study series included 693 women at the stage of bone loss (≥ 45 years of age), defined based on the observed patterns of age-related BMD changes in the KNHANES. Geometric bone structure properties, including hip axis length (HAL) and femur neck width (FNW), were measured using hip dual-energy X-ray absorptiometry scans and were combined with BMD, body weight, and height to create composite indices of femur neck strength relative to load in three different failure modes: compression (CSI), bending (BSI), and impact strength indices (ISI).

RESULTS

After adjustment for age, body mass index (BMI), lifestyle factors, serum 25-hydroxyvitamin D, calcium and phosphorus intake, diabetes, and menopause status, multiple regression analyses revealed that serum ferritin was inversely associated with the BMD values at the lumbar spine and femur neck, and the femur neck cortical thickness. Importantly, in all adjustment models, higher serum ferritin was consistently associated with the lower values for all three femur neck composite indices, such as CSI, BSI, and ISI.

CONCLUSIONS

These data provide the first clinical evidence that increased total body iron stores reflected by higher serum ferritin may be associated with the decrease of bone strength relative to load.

Teriparatide in patients with osteoporosis and type 2 diabetes

Despite evidence for higher fracture risk, clinical effects of osteoporosis treatments in type 2 diabetes (T2D) are largely unknown. Post hoc analyses of the DANCE observational study compared T2D patients and patients without diabetes to assess the effect of teriparatide, an osteoanabolic therapy on skeletal outcomes and safety. Patients included ambulatory men and women with osteoporosis receiving teriparatide 20μg/day SQ up to 24months followed by observation up to 24months. Main outcome measures included nonvertebral fracture incidence comparing 0-6months with 6+ months of teriparatide, change from baseline in BMD and back pain severity, and serious adverse events. Analyses included 4042 patients; 291 with T2D, 3751 without diabetes. Treatment exposure did not differ by group. For T2D patients, fracture incidence was 3.5 per 100 patient-years during 0-6months treatment, and 1.6 during 6months to treatment end (47% of baseline, 95% CI 12-187%); during similar periods, for patients without diabetes, fracture incidence was 3.2 and 1.8 (57% of baseline, 95% CI 39-83%). As determinants of fracture outcome during teriparatide treatment, diabetes was not a significant factor (P=0.858), treatment duration was significant (P=0.003), and the effect of duration was not significantly different between the groups (interaction P=0.792). Increases in spine and total hip BMD did not differ between groups; increase in femoral neck BMD was greater in T2D patients than in patients without diabetes (+0.34 and +0.004g/cm(2), respectively; P=0.014). Back pain severity decreased in both groups. Teriparatide was well tolerated without new safety findings. In conclusion, during teriparatide treatment, reduction in nonvertebral fracture incidence, increase in BMD, and decrease in back pain were similar in T2D and non-diabetic patients.

Association Between Insulin Resistance and Bone Structure in Nondiabetic Postmenopausal Women

CONTEXT

The clinical consequences of insulin resistance and hyperinsulinemia on bone remain largely unknown.

OBJECTIVE

The objective of the study was to evaluate the effect of insulin resistance on peripheral bone geometry, volumetric bone mineral density (vBMD), bone microarchitecture, and estimated bone strength.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included 146 postmenopausal, nondiabetic Caucasian women (mean age 60.3 ± 2.7 y) who were participating in the Study of Women's Health Across the Nation.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURES

High-resolution peripheral quantitative computed tomography was used to assess bone density and microstructure at the distal radius and tibia. Fasting insulin and glucose were measured and insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR), with higher values indicating greater insulin resistance.

RESULTS

There was a negative association between HOMA-IR and bone size and a positive association between HOMA-IR and total vBMD, trabecular vBMD, trabecular thickness, and cortical thickness at the radius and tibia. These relationships remained, even after adjusting for body weight and other potential covariates (eg, time since menopause, cigarette smoking, physical activity, prior use of osteoporosis medications or glucocorticoids).

CONCLUSIONS

In nondiabetic, postmenopausal women, insulin resistance was associated with smaller bone size, greater volumetric bone mineral density, and generally favorable bone microarchitecture at weight-bearing and nonweight-bearing skeletal sites. These associations were independent of body weight and other potential covariates, suggesting that hyperinsulinemia directly affects bone structure independent of obesity and may explain, in part, the higher trabecular bone density and favorable trabecular microarchitecture seen in individuals with type 2 diabetes mellitus.

Association of nonalcoholic fatty liver disease with bone mineral density and serum osteocalcin levels in Korean men

OBJECTIVE

Bone mineral density has been reported to negatively associate with nonalcoholic fatty liver disease. Osteocalcin, a bone formation marker and metabolic regulator, has been previously evaluated as the mediator between bone mineral density and nonalcoholic fatty liver disease. Herein, we aimed to investigate the correlations of nonalcoholic fatty liver disease with bone mineral density and serum osteocalcin levels in Korean men.

METHODS

A total of 859 men (249 and 610 men with and without nonalcoholic fatty liver disease, respectively) were recruited for this retrospective cross-sectional study. All participants underwent hepatic ultrasonography and dual energy X-ray absorptiometry. Anthropometric and biochemical data, including the serum osteocalcin levels and homeostasis model assessment of insulin resistance (HOMA-IR), were collected.

RESULTS

Nonalcoholic fatty liver disease negatively associated with right-hip bone mineral density (odds ratio, 0.797; 95% confidence interval, 0.645-0.984; P=0.035) and serum osteocalcin (odds ratio, 0.948; 95% confidence interval, 0.910-0.988; P=0.011) after adjusting for BMI and HOMA-IR. The mean right-hip bone mineral density was lower in men with versus without nonalcoholic fatty liver disease after adjusting for serum osteocalcin, BMI and HOMA-IR (0.11±0.06 vs. 0.29±0.04; P=0.019).

CONCLUSION

Nonalcoholic fatty liver disease negatively associated with right-hip bone mineral density and serum osteocalcin in Korean men. General population-based prospective studies evaluating the causal relationship between bone metabolism and nonalcoholic fatty liver disease are needed, and the mechanism linking nonalcoholic fatty liver disease to bone mineral density beyond insulin resistance and osteocalcin should be evaluated in the future.

Insulin resistance and composite indices of femoral neck strength in Asians: the fourth Korea National Health and Nutrition Examination Survey (KNHANES IV)

OBJECTIVE

Fracture risk in type 2 diabetes mellitus with insulin resistance is increased, despite relatively preserved bone mineral density (BMD). In this study, we investigated the relationship between insulin resistance and composite indices of femoral neck strength in Koreans.

DESIGN

A population-based, cross-sectional study from the Korea National Health and Nutrition Examination Survey PARTICIPANTS: About 1243 men and 1433 women MEASUREMENTS: Insulin resistance was evaluated using the homoeostasis model assessment-estimated insulin resistance (HOMA-IR) index. Femoral neck width and axis length were measured from hip dual-energy X-ray absorptiometry scans and combined with BMD, weight and height to calculate composite indices of femoral neck strength relative to load: compression (CSI), bending (BSI) and impact strength indices (ISI).

RESULTS

HOMA-IR showed an inverse relationship with CSI, BSI and ISI in both genders before and after adjusting for confounders (P < 0·001-0·029). CSI was more strongly associated with HOMA-IR than BSI and/or ISI in both genders (P < 0·001-0·013). When men were stratified according to HOMA-IR quartiles, all strength indices decreased as the quartile increased, after adjusting for all potential confounders (P for trend <0·001-0·001), whereas CSI and ISI did in women (P for trend = 0·012 and 0·002, respectively). Fasting insulin levels, but not glucose levels, were negatively associated with all strength indices regardless of confounders (P < 0·001-0·044).

CONCLUSIONS

Insulin resistance is associated with low femoral neck strength, particularly against the compressive load. These findings suggest a better approach to evaluate bone health in insulin-resistant individuals.

Diabetes and bone: biological and environmental factors

PURPOSE OF REVIEW

Type 1 and type 2 diabetes mellitus are known to increase fracture risk. It is known that type 1 diabetes mellitus is associated with lower bone mineral density, but for type 2 diabetes mellitus, the real risk of increasing osteoporotic fractures is not explained by bone mineral density, which was found to be normal or paradoxically higher than controls in several studies, thus claiming for further investigations. This review summarizes some of the newest findings about factors that contribute to bone alterations in diabetic patients.

RECENT FINDINGS

Most recent evidences showed that bone of diabetic patients presents a cortical porosity which is not captured by the bidimensional densitometric measurements as performed by dual energy X-ray absorptiometry. Other studies investigated bone matrix searching for molecular mechanisms underlying the reduced bone strength in diabetic patients. The loss of bone biomechanical properties in diabetes has been associated to the glycated collagen matrix induced by hyperglycemia. Other studies analyzed the effect on bone microarchitecture of the most common antidiabetic drugs.

SUMMARY

Disease management of fracture risk in diabetic patients needs new methodologies of assessment that also take into account bone quality and evaluation of clinical risk factors, including balance, visual, and neurological impairments.

Sex-specific differences in progressive glucose intolerance and hip geometry: the Baltimore Longitudinal Study of Aging

Fracture risk is increased in type 2 diabetes mellitus (T2DM). The effect of pre-diabetes and T2DM on bone macroarchitecture and strength has not been well investigated. In this study, we show that in women only, both pre-diabetes and T2DM are associated with decreased hip bending strength and mineralization which might lead to skeletal weakness.

INTRODUCTION

Older men and women with T2DM are at increased risk for fracture despite normal bone mineral density (BMD). The discordance between bone quantity and skeletal fragility has driven investigation into additional determinants of fracture resistance in T2DM. Additionally, the effect of pre-diabetes on bone strength has not been well described. The aim of this study was to determine differences in bone macroarchitecture and strength, measured by hip geometry, in persons with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and T2DM.

METHODS

We performed cross-sectional analyses of older (age >55 years) men (n = 472) and women (n = 473) participating in the Baltimore Longitudinal Study of Aging (BLSA) classified as NGT, IGT, or T2DM based on oral glucose tolerance testing. Bone strength measures included the hip geometry parameters of section modulus (Z), cross-sectional area (CSA), and buckling ratio (BR). Sex-stratified analyses were conducted using adjusted stepwise regression models.

RESULTS

In women, IGT and T2DM were negatively associated with hip geometry parameters including mineralization in cross section (CSA, ß -0.076 and -0.073, respectively; both p < 0.05) and hip bending strength (Z, ß -0.097 and -0.09, respectively; both p < 0.05); conversely, IGT and T2DM were associated with improved compressive strength (BR, ß -0.31 and -0.29, respectively; both p < 0.05). There was no significant association between glycemic status and hip geometry in men.

CONCLUSIONS

In women only, both IGT and T2DM were inversely associated with bone macroarchitecture and measures of bone mineralization and bending strength. The same association between worsening glycemic status and bone strength was not observed in men. These data suggest a differential effect of sex on hip geometry with evolving glucose intolerance.

Parity, lactation, bone strength, and 16-year fracture risk in adult women: findings from the Study of Women's Health Across the Nation (SWAN)

Our objective was to examine the associations of lifetime parity and accumulated length of lactation with bone strength in women prior to the menopause transition and fracture risk during and after the transition. Participants were 2239 pre- or early peri-menopausal women from the Study of Women's Health Across the Nation (SWAN), ages 42-53 years at baseline, who had no childbirths after age 42. Bone mineral density (BMD) was measured in the femoral neck and the lumbar spine at the baseline SWAN visit using dual-energy x-ray absorptiometry, and the composite indices of femoral neck strength relative to load (in three failure modes: compression, bending, and impact) were calculated from femoral neck BMD, femoral neck size, and body size. Data on fractures after age 42 were collected for a median follow-up of 15.7 years (interquartile range, 11.4-18.5 years). In multiple linear regressions adjusted for covariates, lifetime parity was associated positively with femoral neck strength relative to load (0.024 standard deviation (SD) increment in impact strength index per childbirth, p=0.049), but accumulated length of lactation was associated negatively with lumbar spine BMD (0.018 SD decrement per every additional 6 months of lactation, p=0.040). In Cox proportional hazards regressions adjusted for covariates, neither parity nor lactation was associated with fracture hazard after age 42. In conclusion, parity and lactation have little impact on peak bone strength prior to menopause, and do not affect fracture risk after age 42 over 16-year follow-up.

Adult bone strength of children from single-parent families: the Midlife in the United States Study

Bone health may be negatively impacted by childhood socio-environmental circumstances. We examined the independent associations of single-parent childhood and parental death or divorce in childhood with adult bone strength indices. Longer exposure to a single-parent household in childhood was associated with lower bone strength in adulthood.

INTRODUCTION

Because peak bone mass is acquired during childhood, bone health may be negatively impacted by childhood socio-environmental disadvantage. The goal of this study was to determine whether being raised in a single-parent household is associated with lower bone strength in adulthood.

METHODS

Using dual-energy X-ray absorptiometry data from 708 participants (mean age 57 years) in the Midlife in the United States Biomarker Project, we examined the independent associations of composite indices of femoral neck bone strength relative to load (in three failure modes: compression, bending, and impact) in adulthood with the experience of single-parent childhood and parental death or divorce in childhood.

RESULTS

After adjustment for gender, race, menopause transition stage, age, and body mass index, each additional year of single-parent childhood was associated with 0.02 to 0.03 SD lower indices of adult femoral neck strength. In those with 9-16 years of single-parent childhood, the compression strength index was 0.41 SD lower, bending strength index was 0.31 SD lower, and impact strength index was 0.25 SD lower (all p values < 0.05). In contrast, parental death or divorce during childhood was not by itself independently associated with adult bone strength indices. The magnitudes of these associations were unaltered by additional adjustment for lifestyle factors and socioeconomic status in childhood and adulthood.

CONCLUSIONS

Independent of parental death or divorce, growing up in a single-parent household is associated with lower femoral neck bone strength in adulthood, and this association is not entirely explained by childhood or adult socioeconomic conditions or lifestyle choices.

Low skeletal muscle mass associates with low femoral neck strength, especially in older Korean women: the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV)

SUMMARY

Data gathered from a nationally representative cohort demonstrated that subject with low skeletal muscle mass had consistently low femoral neck composite strength indices for compression, bending, and impact, especially in older women, supporting the highly integrated nature of skeletal muscle and bone.

INTRODUCTION

Skeletal muscle and bone interact mechanically and functionally. The present study was performed to investigate the association between muscle mass and femoral neck composite strength indices using a nationally representative cohort.

METHODS

This is a population-based, cross-sectional study from Korea National Health and Nutrition Examination Surveys, including 1,275 Koreans (674 women and 601 men) aged 50 years or older. Femoral neck axis length and width were measured by hip DXA scans and were combined with BMD, body weight, and height to create composite indices of femoral neck strength relative to load in three different failure modes: compression, bending, and impact. Presarcopenia was defined as an appendicular skeletal muscle mass (ASM) divided by body weight that was less than 1 SD below the sex-specific mean for young adults.

RESULTS

After adjusting for confounders, women with presarcopenia had consistently lower indices for compression strength (CSI), bending strength (BSI), and impact strength (ISI) than women without this condition. Men with presarcopenia had a lower ISI value than men without presarcopenia. Multiple regression analyses revealed that lower relative skeletal muscle mass (ASM/weight) associated significantly with lower values for all three femoral neck composite indices in women and with lower CSI and ISI in men.

CONCLUSIONS

These findings provide the first clinical evidence for the notion that age-related low muscle mass may increase the risk of osteoporotic hip fractures by decreasing femoral neck strength relative to load, especially in older women, and support the highly integrated nature of skeletal muscle and bone.

Pleiotropic effects of obesity on fracture risk: the Study of Women's Health Across the Nation

Some aspects of an obese body habitus may protect against fracture risk (higher bone mineral density [BMD] and greater tissue padding), while others may augment that risk (greater impact forces during a fall). To examine these competing pathways, we analyzed data from a multisite, multiethnic cohort of 1924 women, premenopausal or early perimenopausal at baseline. Obesity was defined as baseline body mass index (BMI) > 30 kg/m(2) . Composite indices of femoral neck strength relative to fall impact forces were constructed from DXA-derived bone size, BMD and body size. Incident fractures were ascertained annually during a median follow-up of 9 years. In multivariable linear regression adjusted for covariates, higher BMI was associated with higher BMD but with lower composite strength indices, suggesting that although BMD increases with greater skeletal loading, the increase is not sufficient to compensate for the increase in fall impact forces. During the follow-up, 201 women had fractures. In Cox proportional hazard analyses, obesity was associated with increased fracture hazard adjusted for BMD, consistent with greater fall impact forces in obese individuals. Adjusted for composite indices of femoral neck strength relative to fall impact forces, obesity was associated with decreased fracture hazard, consistent with a protective effect of soft tissue padding. Further adjustment for hip circumference, a surrogate marker of soft tissue padding, attenuated the obesity-fracture association. Our findings support that there are at least three major mechanisms by which obesity influences fracture risk: increased BMD in response to greater skeletal loading, increased impact forces, and greater absorption of impact forces by soft tissue padding.

Type 2 diabetes mellitus and fracture risk

Increased fracture risk, traditionally associated with type 1 diabetes, has lately been of great concern in patients with type 2 diabetes. A variable increase in fracture risk has been reported, ranging from 20% to 3-fold, depending on skeletal site, diabetes duration and study design. Longer disease duration, the presence of diabetic complications, inadequate glycemic control, insulin use and increased risk for falls are all reported to increase fracture risk. Patients with type 2 diabetes display a unique skeletal phenotype with either normal or more frequently increased, bone mineral density and impaired structural and geometric properties. Recently, alterations in bone material properties seem to be the predominant defect leading to increased bone fragility. Accumulation of advanced glycation end-products and changes in collagen cross-linking along with suppression of bone turnover seem to be significant factors impairing bone strength. FRAX score has been reported to underestimate fracture risk and lumbar spine BMD is inadequate in predicting vertebral fractures. Anti-diabetic medications, apart from thiazolidinediones, appear to be safe for the skeleton, although more data are needed. Optimal strategies to reduce skeletal fragility in type 2 diabetic patients are yet to be determined.